Study On The Characteristtics Of Coal-bed Methane Geology In Huainan Xiejiaji Mining Area

CBM is a new clean energy, coal bed methane exploitation and utilization has a very important practical significance to the sustainable development of China’s economy and society. This paper take Xiejiaji mine as the main research area. Based on the theories and methods of CBM field, using the data of production, drilling and experimental analysis, this thesis gives a systematic analysis of CBM geological features in this area.According to migration, occurrence and tectonic characteristics of coalbed methane, the study area was divided into three geological units. Combite with the regional geological background of Xiejiaji mine, three factors are considered during the assessment of the CBM:the coal geological characteristics, the reservoir conditions of coal bed methane, and the gas-controlling geologic factors. Thereby, it is pointed out the CBM geologic characteristics:1. The study area has good coal bed methane formation conditions. The Carboniferous-Permian coal measures strata in this area have stronger hydrocarbongenerating potential, which process abundant organic matter, rich coal andsteady lithology and lithofacies.2. The study area has a good CBM storage conditions. The main coal beds are thick, distributed stability. The cleat of coalbed methane reservoirs are developed,. The vitrinite of maceral in main mining seams is more than60%, have a strong adsorption of CBM.3.The study area has favorable CBM saved conditions. Coal seams and overlying strata mostly are non-permeability rock, which is propitious to the prevention of the dissipation of CBM. Fault structure play an obvious effect on gas content in this area, there are current distribution of coalbed gas content near the two fault walls. This area has simple hydrology geological conditions, the groundwater flow is slow, blocking the transport of coalbed methane, conducive to coalbed methane’s preservation.4. The distribution of coalbed methane in this area is uneven. In the vertical direction, with the increase of depth, the gas content showed a tendency increase, in the same geological unit. In the horizontal direction, in different coalbed methane unit, the gas content and gas component are different. There are some differences in controlling factors of gas distribution, the gas content in second and third unit are higher than first unit.